[考試總結]noip模擬6
阿新 • • 發佈：2021-06-11
我好菜啊
- 真上次第二這次倒二。。。
因為昨天還沒有改完所有的題所以就留到今天來寫部落格了
這次考試總結的教訓有很多吧，反正處處體現XIN某人的laji，自己考試的是後本以為一共四個題目，三個題目都沒有看懂，然而考試結束以後才發現，自己是四個題目都沒有看懂。cao
又成10分XIN了
不管了，菜就是菜了。
以後看到題目中不懂的玩意兒也不應該害怕，什麼曼哈頓距離，自己看看樣例就知道了，不應該棄掉的，並且在手推樣例認為樣例有鍋的時候也應該返回去去看看題目，而不是一味地認為題目有鍋。。。
來自 \(\LaTeX\) 的侮辱
T1:
什麼laji曼哈頓距離，反正對角線就完了。
。。。。。
然後記錄每一個矩形，按照 \(x\)
為什麼之考慮所有矩形不相連就有 \(65pts\) 啊！！！
。。。。。
code：
#include<iostream> #include<cstdlib> #include<cstdio> #include<cmath> #include<algorithm> #include<cstring> #include<queue> #include<map> using namespace std; #define int long long #define debug cout<<"debug"<<endl #define freopen eat2 = freopen #define scanf eat1 = scanf namespace xin_io { #define gc() p1 == p2 and (p2 = (p1 = buf) + fread(buf,1,1<<20,stdin),p1 == p2) ? EOF : *p1++ #define scanf eat1 = scanf #define freopen eat2 = freopen char buf[1<<20],*p1 = buf,*p2 = buf;FILE *eat2; inline void openfile() {freopen("t.txt","r",stdin);} inline void outfile(){freopen("o.txt","w",stdout);} inline int get() { int s = 0,f = 1;register char ch = gc(); while(!isdigit(ch)) {if(ch == '-') f = -1;ch = gc();} while(isdigit(ch)) {s = s * 10 + ch - '0';ch = gc();}return s * f; } } using namespace xin_io; int eat1; static const int maxn = 1e5+10; #include<ctime> #include<cstring> #define mp make_pair #define xd xin_data #define rp(i,x,y) for(register int i=x;i<=y;++i) #define bd(i,x,y) for(register int i=x;i>=y;--i) namespace xin { class xin_data { public: int x1,x2,y1,y2; friend bool operator < (xin_data x,xin_data y) {return x.x1 == y.x1 ? x.y1 < y.y1 : x.x1 < y.x1;} }p[maxn]; int n,ans = 0; inline int find(int x,int y) { int tog; if(p[x].x2 + 1 == p[y].x1) { if(p[y].y1 > p[x].y2 or p[y].y2 < p[x].y1) return 0; tog = abs(max(p[y].y2,p[x].y2) - min(p[y].y1,p[x].y1) + 1) - abs(p[y].y2 - p[x].y2) - abs(p[y].y1 - p[x].y1); if(p[x].y1 == p[y].y1 and p[x].y2 == p[y].y2) return tog * 2; if(p[x].y2 == p[y].y2 or p[x].y1 == p[y].y1) return tog * 2 - 1; return tog * 2; } if(p[x].y2 + 1 == p[y].y1) { if(p[y].x1 > p[x].x2 or p[x].x1 > p[y].x2) return 0; tog = abs(max(p[x].x2,p[y].x2) - min(p[x].x1,p[y].x1) + 1) - abs(p[x].x2 - p[y].x2) - abs(p[x].x1 - p[y].x1); if(p[x].x1 == p[y].x1 and p[x].x2 == p[y].x2) return tog * 2; if(p[x].x2 == p[y].x2 or p[x].x1 == p[y].x1) return tog * 2 - 1; return tog * 2; } return 0; } inline short main() { #ifndef ONLINE_JUDGE openfile(); #endif n = get(); rp(i,1,n) p[i].x1 = get(),p[i].y1 = get(),p[i].x2 = get(),p[i].y2 = get(),ans += (p[i].x2 - p[i].x1) * (p[i].y2 - p[i].y1) * 2; sort(p+1,p+n+1); // rp(i,1,n) cout<<"i = "<<i<<" p[i].x1 = "<<p[i].x1<<" p[i].y1 = "<<p[i].y1<<" p[i].x2 = "<<p[i].x2<<" p[i].y2 = "<<p[i].y2<<endl; rp(i,1,n) rp(j,i+1,n) { if(p[j].x1 - p[i].x2 > 1 ) break; if(min(p[i].x2,p[j].x2) - max(p[i].x1,p[j].x1) >= 0 and (p[i].y2 == p[j].y1 - 1 or p[j].y2 == p[i].y1 - 1)) { if(p[i].y2 == p[j].y1 - 1) { ans += (min(p[i].x2,p[j].x2) - max(p[i].x1,p[j].x1)) * 2; if(p[i].x1 != p[j].x1) ans ++; if(p[i].x2 != p[j].x2) ans ++; } if(p[j].y2 == p[i].y1 - 1) { ans += (min(p[i].x2,p[j].x2) - max(p[i].x1,p[j].x1)) * 2; if(p[i].x1 != p[j].x1) ans ++; if(p[i].x2 != p[j].x2) ans ++; } } if(min(p[i].y2,p[j].y2) - max(p[i].y1 ,p[j].y1) >= 0 and (p[i].x2 == p[j].x1 - 1 or p[j].x2 == p[i].x1 - 1)) { if(p[i].x2 == p[j].x1 - 1) { ans += (min(p[i].y2,p[j].y2) - max(p[i].y1,p[j].y1)) * 2; if(p[i].y1 != p[j].y1) ans ++; if(p[i].y2 != p[j].y2) ans ++; } if(p[j].x2 == p[i].x1 - 1) { ans += (min(p[i].y2,p[j].y2) - max(p[i].y1,p[j].y1)) * 2; if(p[i].y1 != p[j].y1) ans ++; if(p[i].y2 != p[j].y2) ans ++; } } if(p[i].x2 == p[j].x1 - 1 and (p[i].y2 == p[j].y1 - 1 or p[i].y1 == p[j].y2 + 1)) ans++; ///cout<<"i = "<<i<<" ans = "<<ans<<endl; } cout<<ans<<endl; return 0; } } signed main() {return xin::main();}
T2:
。。。。。
我不會告訴你我還沒有調出來。。。。
T3:
又是 \(dark\) 佬。。。。
設 \(f\) 表示概率，那麼我們就可以知道：
\[f_i=f_{i-1}-sum_{i-1} \]\[sum_{i-1} = \sum_{i=1}^{i-1} f_i \]\[ans=\sum w_i * f_i \]。。。。
所以\(code:\)
#include<iostream> #include<cstdlib> #include<cstdio> #include<cmath> #include<algorithm> #include<cstring> #include<queue> using namespace std; #define int long long #define debug cout<<"debug"<<endl #define freopen eat2 = freopen #define scanf eat1 = scanf namespace xin_io { #define gc() p1 == p2 and (p2 = (p1 = buf) + fread(buf,1,1<<20,stdin),p1 == p2) ? EOF : *p1++ #define scanf eat1 = scanf #define freopen eat2 = freopen char buf[1<<20],*p1 = buf,*p2 = buf;FILE *eat2; inline void openfile() {freopen("t.txt","r",stdin);} inline void outfile(){freopen("o.txt","w",stdout);} inline int get() { int s = 0,f = 1;register char ch = gc(); while(!isdigit(ch)) {if(ch == '-') f = -1;ch = gc();} while(isdigit(ch)) {s = s * 10 + ch - '0';ch = gc();}return s * f; } } using namespace xin_io; int eat1; static const int maxn = 1e5+10,mod = 1000000007; #include<ctime> #include<cstring> namespace xin { int n,m,k; int w[maxn]; inline int ksm(int x,int y,int mod) { int ret = 1; while(y){if(y & 1) ret = ret * x % mod;x = x * x % mod; y >>= 1;} return ret; } inline int inv(int x) {return ksm(x,mod-2,mod);} int f[maxn],ans,s; inline short main() { #ifndef ONLINE_JUDGE openfile(); #endif n = get(); m = get(); k = get(); int day = (n - k + 1) > 0 ? (n - k + 1) : 0; for(register int i=1;i<=m;++i) w[i] = get();//,w[i] = w[i-1] + w[i]; for(register int i=1;i<=m;++i) { s = s + f[i-1] % mod; f[i] = (ksm(i,k,mod) * inv(ksm(m,k,mod)) - s) % mod; ans = (ans + w[i] * f[i]) % mod; } ans = ans * day % mod; cout<<ans<<endl; return 0; } } signed main() {return xin::main();}
T4:
暴搜。。。
只需要考慮每一個起始點和每一個結束點。。。
然後開始暴搜。。。
不需要建邊，只要維護一個 \(cost\) 陣列就行了。。。
\(cost\) 初始值就設定為 \(0x7f7f7f7f7f\) 就行。。。
最後取得最小值。
一共 \(n <= 12\) ，然而 \(m\) 卻$ <=2000$ ，重邊很多。。。
之後就有 \(70pts\) 了
#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
#define int long long
#define debug cout<<"debug"<<endl
#define freopen eat2 = freopen
#define scanf eat1 = scanf
namespace xin_io
{
#define gc() p1 == p2 and (p2 = (p1 = buf) + fread(buf,1,1<<20,stdin),p1 == p2) ? EOF : *p1++
#define scanf eat1 = scanf
#define freopen eat2 = freopen
char buf[1<<20],*p1 = buf,*p2 = buf;FILE *eat2;
inline void openfile() {freopen("t.txt","r",stdin);} inline void outfile(){freopen("o.txt","w",stdout);}
inline int get()
{
int s = 0,f = 1;register char ch = gc();
while(!isdigit(ch))
{if(ch == '-') f = -1;ch = gc();}
while(isdigit(ch))
{s = s * 10 + ch - '0';ch = gc();}return s * f;
}
}
using namespace xin_io; int eat1;
static const int maxn = 13;
#include<ctime>
#include<cstring>
#define m(c,num) memset(c,num,sizeof c)
namespace xin
{
int n,m;
int c[maxn][maxn];
int temp;
int num[maxn];
int ans = 0x7f7f7f7f;
void dfs(int now,int cnt)
{
if(cnt == n)
{
ans = min(ans,temp);
return ;
}
if(temp >= ans) return ;
for(register int i=1;i<=n;++i)
if(!num[i])
for(register int j=1;j<=n;++j)
if(c[i][j] != 0x7f7f7f7f and i != j and num[j])
{
temp += num[j] * c[i][j]; num[i] = num[j] + 1;
dfs(i,cnt+1);
temp -= num[j] * c[i][j]; num[i] = 0;
}
}
inline short main()
{
#ifndef ONLINE_JUDGE
openfile();
#endif
n = get(); m = get(); for(register int i=1;i<=n;++i) for(register int j=0;j<=n;++j) c[i][j] = 0x7f7f7f7f;
for(register int i=1;i<=m;++i)
{
register int x = get(),y = get();
c[x][y] = c[y][x] = min(c[x][y],get());
}
for(register int i=1;i<=n;++i)
{num[i] = 1; dfs(i,1); num[i] = 0;}
cout<<ans<<endl;
return 0;
}
}
signed main() {return xin::main();}
之後考慮正解，實際上就是有枝就剪。
然後飛快。。。
#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
//#define int long long
#define debug cout<<"debug"<<endl
#define freopen eat2 = freopen
#define scanf eat1 = scanf
#define inf 0x7f7f7f7f
namespace xin_io
{
#define gc() p1 == p2 and (p2 = (p1 = buf) + fread(buf,1,1<<20,stdin),p1 == p2) ? EOF : *p1++
#define scanf eat1 = scanf
#define freopen eat2 = freopen
char buf[1<<20],*p1 = buf,*p2 = buf;FILE *eat2;
inline void openfile() {freopen("t.txt","r",stdin);} inline void outfile(){freopen("o.txt","w",stdout);}
inline int get()
{
int s = 0,f = 1;register char ch = gc();
while(!isdigit(ch))
{if(ch == '-') f = -1;ch = gc();}
while(isdigit(ch))
{s = s * 10 + ch - '0';ch = gc();}return s * f;
}
}
using namespace xin_io; int eat1;
static const int maxn = 13;
#include<ctime>
#include<cstring>
#define m(c,num) memset(c,num,sizeof c)
namespace xin
{
int n,m;
int vis[maxn],rea[maxn][maxn],tot;
int c[maxn][maxn],d[maxn],l[maxn];
int temp,cnt;
int ans = inf;
inline void dfs(int num,int nd)
{
for(register int i=num;i<=cnt;++i)
{
if(tot + temp * l[vis[i]] >= ans) return;
for(register int j=nd;j<=d[vis[i]];++j)
if(!l[rea[vis[i]][j]])
{
vis[++cnt] = rea[vis[i]][j];
temp -= c[vis[cnt]][rea[vis[cnt]][1]];
tot += c[vis[i]][vis[cnt]] * l[vis[i]];
l[vis[cnt]] = l[vis[i]] + 1;
dfs(i,j+1);
temp += c[vis[cnt]][rea[vis[cnt]][1]];
tot -= c[vis[i]][vis[cnt]] * l[vis[i]];
l[vis[cnt]] = 0;cnt--;
}
nd = 1;
}
if(cnt == n) {ans = min(ans,tot);return ;}
}
int pai;
inline bool comp(int x,int y) {return c[pai][x] < c[pai][y];}
inline short main()
{
#ifndef ONLINE_JUDGE
openfile();
#endif
n = get(); m = get(); for(register int i=1;i<=n;++i) for(register int j=1;j<=n;++j) c[i][j] = inf;
for(register int i=1;i<=m;++i)
{
register int x = get(),y = get(),z = get();
if(z <= c[x][y])
{
if(c[x][y] == inf) rea[x][++d[x]] = y,rea[y][++d[y]] = x;
c[x][y] = c[y][x] = z;
}
}
for(register int i=1;i<=n;++i)
{
pai = i; sort(rea[i]+1,rea[i]+d[i]+1,comp);
temp += c[i][rea[i][1]];
}
for(register int i=1;i<=n;++i)
{
cnt = 1; tot = 0;
temp -= c[i][rea[i][1]];
vis[1] = i;
l[i] = 1;
dfs(1,1);
temp += c[i][rea[i][1]];
l[i] = 0;
}
printf("%d\n",ans);
return 0;
}
}
signed main() {return xin::main();}